1. Field of the Invention
The present invention relates to a disk holding device and disk processor. More particularly, the present invention relates to a disk holding device for holding a disk on a lower side and capable of preventing unwanted drop of a disk from a disk holding mechanism, and a disk processor.
2. Description Related to the Prior Art
A disk processor is known and commercially marketed in the field of instruments for data recording. The disk processor includes a data writer for writing data to a great number of disks, such as CDs and DVDs, and also includes a label printer for printing a label on each of the disks. An unprocessed disk storage unit is included in the disk processor for stacking unprocessed disk. A disk holding device or disk holding arm takes up disks one after another. Each disk is moved to the data writer, transferred from the data writer to the label printer, and transferred from the label printer to a processed disk storage unit.
The disk holding device includes coupling levers or disk holding levers for holding a disk. There is a center hole in a disk. The coupling levers are entered in and engaged with the center hole for holding. There have been various suggested structures of the coupling levers for the purpose of exactly holding each one of disks in a discrete manner.
U.S. Pat. Pub. No. 2007/0267881 (corresponding to JP-A 2007-310920) discloses a set of three coupling levers insertable in the center hole of a disk for contacting an edge surface of the center hole. Among the coupling levers, two have a contact surface for contacting the edge surface of the center hole. The contact surface has a size greater than a thickness of the disk. A remaining one of the coupling levers has a contact surface for contacting the edge surface of the center hole, the contact surface has a size smaller than the thickness of the disk. This is for the purpose of avoiding simultaneous holding of two disks.
According to the above-indicated document, a disk is held by pressing the coupling levers onto the edge surface of the center hole without use of other supporting structure. Should considerable shock occur to the coupling levers, the disk may be disengaged, specifically one of those having a smaller size of a contact surface than a thickness of the disk. Skew occurs to the disk which may drop away from the coupling levers in a very unacceptable situation.